在已安装二进制movit2的情况下使用自编译moveit2

• 在已安装二进制movit2的情况下，想使用自编译moveit2，只要引入一下自编译moveit2库的环境变量即可。主要是想搞明白这个过程发生了什么，也就是引入环境后有什么变化，以及如何对编译过程产生影响

一、setup.bash流程

• 所有资料上都说setup.bash作用就是添加环境，其实就是将对应的地址添加到不同的环境变量当中了，这里主要想分析一下这个过程是如何实现的
• 主要 关注的环境变量是LD_LIBRARY_PATH、CMAKE_PREFIX_PATH、AMENT_PREFIX_PATH

1、运行source ./install/setup.bash效果

==========运行source ./install/setup.bash前==========
~/ws_moveit2$ echo $LD_LIBRARY_PATH
/usr/local/etherlab/lib:/opt/ros/humble/opt/rviz_ogre_vendor/lib:/opt/ros/humble/lib/x86_64-linux-gnu:/opt/ros/humble/lib~/ws_moveit2$ echo $CMAKE_PREFIX_PATH~/ws_moveit2$ echo $AMENT_PREFIX_PATH
/opt/ros/humble

• 运行后自己包中的所有lib文件就添加到LD_LIBRARY_PATH变量中，类似~/ws_moveit2/install/moveit_ros_planning_interface/lib的地址
• CMAKE_PREFIX_PATH和AMENT_PREFIX_PATH变量添加了很多类似~/ws_moveit2/install/moveit_ros_planning_interface的地址

2、./install/setup.bash文件分析

• 文件中用的是shell语言，跟命令行中用的一样。不过两个语法略有不同，属于不同的shell类型，大部分差不多

（1）定义_colcon_prefix_chain_bash_source_script()函数

_colcon_prefix_chain_bash_source_script() {if [ -f "$1" ]; thenif [ -n "$COLCON_TRACE" ]; thenecho "# . \"$1\""fi. "$1"  elseecho "not found: \"$1\"" 1>&2fi
}

（2）加载基础ros环境

COLCON_CURRENT_PREFIX="/opt/ros/humble"  #系统中ros的安装位置
_colcon_prefix_chain_bash_source_script "$COLCON_CURRENT_PREFIX/local_setup.bash" #运行对应的bash文件

• 每个工作空间都默认加载了基础的环境变量

（3）加载当前工作空间的环境

COLCON_CURRENT_PREFIX="$(builtin cd "`dirname "${BASH_SOURCE[0]}"`" > /dev/null && pwd)"
_colcon_prefix_chain_bash_source_script "$COLCON_CURRENT_PREFIX/local_setup.bash"

• 这里比较复杂的就是第一行，测试一下就可以那段命令就是运行

builtin cd "`dirname "${BASH_SOURCE[0]}"`" > /dev/null && pwd

结果就是返回了当前路径

~/ws_moveit2/install

• 具体语法解读
  builtin cd ： 使用内置命令cd
  ${BASH_SOURCE[0]} ： 这个变量显示此脚本的位置包括文件名
  dirname ： 取出地址，即取出文件名
  ‘ ’ ： 先执行反引号内部的命令
  /dev/null ： 把输出放入黑洞设备，也就是不输出
  上面命令一起就是cd到当前，然后再用pwd输出即可传递给COLCON_CURRENT_PREFIX

（4）删除定义的变量和函数

unset COLCON_CURRENT_PREFIX
unset _colcon_prefix_chain_bash_source_script

• 删除定义的变量和函数

3、./install/local_setup.bash文件分析

（1）添加地址到环境变量

_colcon_prefix_bash_prepend_unique_value() {# arguments_listname="$1"_value="$2"# get values from variableeval _values=\"\$$_listname\"# backup the field separator_colcon_prefix_bash_prepend_unique_value_IFS="$IFS"IFS=":"# start with the new value_all_values="$_value"_contained_value=""# iterate over existing values in the variablefor _item in $_values; do# ignore empty stringsif [ -z "$_item" ]; thencontinuefi# ignore duplicates of _valueif [ "$_item" = "$_value" ]; then_contained_value=1continuefi# keep non-duplicate values_all_values="$_all_values:$_item"doneunset _itemif [ -z "$_contained_value" ]; thenif [ -n "$COLCON_TRACE" ]; thenif [ "$_all_values" = "$_value" ]; thenecho "export $_listname=$_value"elseecho "export $_listname=$_value:\$$_listname"fififiunset _contained_value# restore the field separatorIFS="$_colcon_prefix_bash_prepend_unique_value_IFS"unset _colcon_prefix_bash_prepend_unique_value_IFS# export the updated variableeval export $_listname=\"$_all_values\"unset _all_valuesunset _valuesunset _valueunset _listname
}

（2）添加前缀地址到COLCON_PREFIX_PATH

_colcon_prefix_bash_prepend_unique_value COLCON_PREFIX_PATH "$_colcon_prefix_bash_COLCON_CURRENT_PREFIX"
unset _colcon_prefix_bash_prepend_unique_value

（3）检查python环境变量

if [ -n "$COLCON_PYTHON_EXECUTABLE" ]; thenif [ ! -f "$COLCON_PYTHON_EXECUTABLE" ]; thenecho "error: COLCON_PYTHON_EXECUTABLE '$COLCON_PYTHON_EXECUTABLE' doesn't exist"return 1fi_colcon_python_executable="$COLCON_PYTHON_EXECUTABLE"
else# try the Python executable known at configure time_colcon_python_executable="/usr/bin/python3"# if it doesn't exist try a fall backif [ ! -f "$_colcon_python_executable" ]; thenif ! /usr/bin/env python3 --version > /dev/null 2> /dev/null; thenecho "error: unable to find python3 executable"return 1fi_colcon_python_executable=`/usr/bin/env python3 -c "import sys; print(sys.executable)"`fi
fi

（4）加载另外的bash脚本，并根据COLCON_TRACE决定是否输出调试信息

• 下面这个代码不是原版，有一些调试信息

echo "==========================="
echo "2"
echo $1
echo "3"
echo $COLCON_TRACE
_colcon_prefix_sh_source_script() {if [ -f "$1" ]; thenif [ -n "$COLCON_TRACE" ]; thenecho "# . \"$1\""fiecho "source \"$1\"". "$1"elseecho "not found: \"$1\"" 1>&2fi
}echo "===========================1"
echo "${_colcon_ordered_commands}"
# get all commands in topological order
_colcon_ordered_commands="$($_colcon_python_executable "$_colcon_prefix_bash_COLCON_CURRENT_PREFIX/_local_setup_util_sh.py" sh bash)"echo "===========================1.5"
echo "${_colcon_ordered_commands}"unset _colcon_python_executable
if [ -n "$COLCON_TRACE" ]; thenecho "$(declare -f _colcon_prefix_sh_source_script)"echo "# Execute generated script:"echo "# <<<"echo "${_colcon_ordered_commands}"echo "# >>>"echo "unset _colcon_prefix_sh_source_script"
fi
echo "===========================2"
echo $AMENT_PREFIX_PATH
echo "===========================3"
echo "${_colcon_ordered_commands}"
eval "${_colcon_ordered_commands}"
unset _colcon_ordered_commandsunset _colcon_prefix_sh_source_scriptunset _colcon_prefix_bash_COLCON_CURRENT_PREFIX
echo "==========================="
echo $AMENT_PREFIX_PATH

• 下面这行运行了_local_setup_util_sh.py文件，生成了添加地址到指定环境变量的命令将其存到_colcon_ordered_commands

_colcon_ordered_commands="$($_colcon_python_executable "$_colcon_prefix_bash_COLCON_CURRENT_PREFIX/_local_setup_util_sh.py" sh bash)"

• 下面这步则是直接执行_colcon_ordered_commands

eval "${_colcon_ordered_commands}"

二、find_package流程

相关资料：

• https://blog.csdn.net/weixin_41652700/article/details/128914776?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522a7d6f436d89e18bbe78a29bb97f8df50%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=a7d6f436d89e18bbe78a29bb97f8df50&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_blogfirst_rank_ecpm_v1~rank_v31_ecpm-1-128914776-null-null.nonecase&utm_term=cmake&spm=1018.2226.3001.4450
• https://blog.csdn.net/m0_73640344/article/details/144246881

1、 find_package搜索地址

• find_package实际上是在找对应的.cmake文件，这些文件会生成对应的_DIR、_LIB、_INCLUDE环境变量名。我在写一个moveit相关代码时，cmakelist中有如下内容

find_package(moveit_ros_planning_interface REQUIRED)

• 这个搜索的地址是~/ws_moveit2/install/moveit_ros_planning_interface/share/moveit_ros_planning_interface/cmake

2、正常编译结果

message("==============find_package前=========")
message("moveit_ros_planning_interface_FOUND: ${moveit_ros_planning_interface_FOUND}")
message("moveit_ros_planning_interface_INCLUDE_DIRS: ${moveit_ros_planning_interface_INCLUDE_DIRS}")
message("moveit_ros_planning_interface_LIBRARIES: ${moveit_ros_planning_interface_LIBRARIES}")
message("moveit_ros_planning_interface_LIBRARY_DIRS: ${moveit_ros_planning_interface_LIBRARY_DIRS}")
message("moveit_ros_planning_interface_VERSION: ${moveit_ros_planning_interface_VERSION}")
message("moveit_ros_planning_interface_DIR: ${moveit_ros_planning_interface_DIR}")
find_package(moveit_ros_planning_interface REQUIRED)
message("==============find_package后=========")
message("moveit_ros_planning_interface_FOUND: ${moveit_ros_planning_interface_FOUND}")
message("moveit_ros_planning_interface_INCLUDE_DIRS: ${moveit_ros_planning_interface_INCLUDE_DIRS}")
message("moveit_ros_planning_interface_LIBRARIES: ${moveit_ros_planning_interface_LIBRARIES}")
message("moveit_ros_planning_interface_LIBRARY_DIRS: ${moveit_ros_planning_interface_LIBRARY_DIRS}")
message("moveit_ros_planning_interface_VERSION: ${moveit_ros_planning_interface_VERSION}")
message("moveit_ros_planning_interface_DIR: ${moveit_ros_planning_interface_DIR}")

• 在find_package前这些变量都不存在
• 没有引入手动编译moveit的工作空间的环境变量，所以在find_package后的环境变量都是在/opt/ros/humle中的，以下是其中的一部分

moveit_ros_planning_interface_FOUND: 1    #找到包
moveit_ros_planning_interface_INCLUDE_DIRS: /opt/ros/humble/include/geometry_msgs;/opt/ros/humble/include/moveit_msgs;/usr/include/bullet;/opt/ros/humble/include;   #头文件地址
moveit_ros_planning_interface_LIBRARIES: /opt/ros/humble/lib/libbuiltin_interfaces__rosidl_generator_c.so;/opt/ros/humble/lib/libbuiltin_interfaces__rosidl_typesupport_fastrtps_c.so;   #库文件
moveit_ros_planning_interface_LIBRARY_DIRS:             #空
moveit_ros_planning_interface_VERSION: 2.5.8    #版本
moveit_ros_planning_interface_DIR: /opt/ros/humble/share/moveit_ros_planning_interface/cmake   #cmake地址

3、使用手动编译moveit2

• 关键就是添加set(moveit_ros_planning_interface_DIR “~/ws_moveit2/install/moveit_ros_planning_interface/share/moveit_ros_planning_interface/cmake”)
• 然后将缺失的so文件添加到LD_LIBRARY_PATH环境变量，这一步也可以用cmake中连接器的相关语法，根本原因在于虽然告诉用find_package告诉了编译器怎么编译（比如CMAKE_CURRENT_SOURCE_DIR等变量），但是和环境变量相关的连接过程还是没有变化，所以要手动添加环境或者在连接器上给出具体位置（最简单的还是直接source运行一下手动编译moveit的bash文件）

4、自写库使用find_package()

资料：
https://zhuanlan.zhihu.com/p/669872914
https://www.cnblogs.com/linxmouse/p/16778116.html

• find_packagge()有模块和配置两种模式。模块模式一般就是自己写的cmake文件，一般是Find<package_name>.cmake文件格式。配置模式就是第三方库官方提供的cmake文件，一般是<package_name>Config.cmake格式。

（1）自写库

• cpp文件、h头文件和CMakeList文件都跟一般代码一样，只是生成库文件。关键就是在cmake文件中添加一些变量。

src/MyLibrary.cpp

#include "MyLibrary.h"
#include <iostream>namespace MyLibrary {void printMessage() {std::cout << "Hello from MyLibrary!" << std::endl;}
}

include/MyLibrary.h

#ifndef MYLIBRARY_H
#define MYLIBRARY_Hnamespace MyLibrary {void printMessage();
}#endif // MYLIBRARY_H

CMakeLists.txt

cmake_minimum_required(VERSION 3.10)
project(MyLibrary VERSION 1.0)# 添加库
add_library(MyLibrary src/MyLibrary.cpp)# 包含头文件目录
target_include_directories(MyLibrary PUBLIC include)

cmake/FindMyLibrary.cmake

set(MyLibrary_FOUND true)
set(MyLibrary_INCLUDE_DIR /home/wangyuanhao/communication_with_thread/find_package_test/include/)
set(MyLibrary_LIBRARIES_DIR /home/wangyuanhao/communication_with_thread/find_package_test/build/)

（2）调用自写库

• find_package只是调用了cmake文件，只是会再一些特定路径下搜索，用include直接调用cmake即可。

src/main.cpp

#include <MyLibrary.h>int main() {MyLibrary::printMessage();return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.10)
project(MyApp)# 查找 MyLibrary
set(CMAKE_MODULE_PATH /home/wangyuanhao/communication_with_thread/find_package_test/cmake)  #将cmake路径添加到模块路径CMAKE_MODULE_PATH，这样find_package才能找到
message(CMAKE_MODULE_PATH:${CMAKE_MODULE_PATH})find_package(MyLibrary REQUIRED)
#include(/home/wangyuanhao/communication_with_thread/find_package_test/cmake/FindMyLibrary.cmake)#跟find_package效果一样message(MyLibrary_INCLUDE_DIR:${MyLibrary_INCLUDE_DIR})# 添加可执行文件
add_executable(MyApp src/main.cpp)# 链接 MyLibrary
target_link_libraries(MyApp PRIVATE /home/wangyuanhao/communication_with_thread/find_package_test/build/libMyLibrary.a)if (MyLibrary_INCLUDE_DIR)target_include_directories(MyApp PRIVATE ${MyLibrary_INCLUDE_DIR})
endif()